Advanced monitoring and control of anaerobic wastewater treatment plants: fault detection and isolation

2001 ◽  
Vol 43 (7) ◽  
pp. 183-190 ◽  
Author(s):  
J-Ph Steyer ◽  
A. Genovesi ◽  
J. Harmand
Keyword(s):  
Wastewater Treatment ◽  
Fault Detection ◽  
Wastewater Treatment Plants ◽  
Real Life ◽  
Practical Interest ◽  
Fault Detection And Isolation ◽  
Monitoring And Control ◽  
On Line ◽  
And Control ◽  
Large Improvement

In this paper, a fault detection and isolation approach using fuzzy logic is described for on-line analysis of problems occurring in anaerobic digestion processes. The measurements available on the process are preprocessed to build a vector of fault residuals indicating the magnitude of the problems. This vector is classified into a prespecified category (i.e., a class) which is a state of the system, according to discrimination fuzzy rules. Three different types of classes were defined in a hierarchical structure : sensors faults, sub-process faults and process faults. This approach was developed to handle in real time both technical and biological problems. Demonstration of the practical interest of this study was made using real life experiments and large improvement of the reliability and safety of the process was obtained, thus optimizing the overall wastewater treatment.

On-line monitoring equipment for wastewater treatment processes: state of the art

2003 ◽  
Vol 47 (2) ◽  
pp. 1-34 ◽  
Author(s):  
P.A. Vanrolleghem ◽  
D.S. Lee
Keyword(s):  
Wastewater Treatment ◽  
Control Systems ◽  
Model Calibration ◽  
Wastewater Treatment Plants ◽  
Monitoring And Control ◽  
Monitoring Equipment ◽  
Automatic Control Systems ◽  
Treatment Processes ◽  
On Line ◽  
And Control

A (non-exhaustive) survey of new and existing technologies for the monitoring of wastewater treatment plants is presented. Emphasis is given to the way these sensors can provide insight in the ongoing (bio-) processes. Three different uses for sensors can be found: for monitoring (operator support), in automatic control systems and as tools for plant auditing/optimization/modelling by consultants. From this, sensors have been classified in two basic types: (i) reliable, simple and low maintenance sensors for day-to-day monitoring and control and (ii) advanced, higher maintenance sensors that are used in auditing, model calibration and optimisation. The paper is organized according to the typical unit processes of biological wastewater treatment systems: anaerobic digestion, activated sludge, nutrient removal and sedimentation. Attention is drawn to a number of practical problems associated with the use of sophisticated sensors in the harsh (dirty) conditions of wastewater treatment processes. The use of autocalibration and built-in sensor checks, cleaning systems and reliable sample preparation units is illustrated. The paper ends with a discussion of the applicability of the different sensors.

Advanced monitoring and control of anaerobic wastewater treatment plants: diagnosis and supervision by a fuzzy-based expert system

2001 ◽  
Vol 43 (7) ◽  
pp. 191-198 ◽  
Author(s):  
A. Puñal ◽  
J. Rodríguez ◽  
A. Franco ◽  
E. F. Carrasco ◽  
E. Roca ◽  
...  
Keyword(s):  
Expert System ◽  
Expert Knowledge ◽  
Wastewater Treatment Plants ◽  
Rule Base ◽  
Monitoring And Control ◽  
Anaerobic Digesters ◽  
On Line ◽  
And Control ◽  
Logic Inference ◽  
Microsoft Windows

A fuzzy-based expert system (ES) for the diagnosis and supervision for anaerobic digesters is presented. The system was developed in a Microsoft Windows support using fuzzy logic inference together with a rule base for the implementation of expert knowledge. The ES runs on-line through three main modules, which determine the state and trend of the process, and the best set points for the actuation on the final control elements of the plant. Two further modules run in parallel, when they are required by the operator, using off-line and on-line information for the detection of inhibition due to toxic compounds in the process and for the validation of the on-line diagnosis. The diagnosis and supervision ES was tuned up in order to adjust the membership functions describing the process, and lately tested, running on-line, to study the response of the rule base.

Feedforward aeration control of a Biocos wastewater treatment plant

2001 ◽  
Vol 43 (3) ◽  
pp. 85-91 ◽  
Author(s):  
B. Wett ◽  
K. Ingerie
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Aeration Time ◽  
Aeration System ◽  
On Line ◽  
Nitrogen Elimination ◽  
And Control ◽  
Influent Flow ◽  
Aeration Control

The Biocos strategy as a cyclical time controlled activated sludge system shows a great variability in operation and control. One topic such a type of treatment plant has to deal with is the optimum relation between aerobic and anoxic conditions. The aeration control has to adapt the length of the nitrification phases to the current constraints in order to save operational costs and maximise nitrogen elimination. Since wastewater treatment plants up to a certain size are usually not equipped with on-line nitrogen probes, influent flow and temperature can be taken as control parameters for the aeration system. The defined relation between influent flow and ammonia load is based on measurements and the relation between ammonia load and required aeration time is model based.

Standard signal processing using enriched sensor information for WWTP monitoring and control

2008 ◽  
Vol 57 (7) ◽  
pp. 1053-1060 ◽  
Author(s):  
I. Irizar ◽  
J. Alferes ◽  
L. Larrea ◽  
E. Ayesa
Keyword(s):  
Signal Processing ◽  
Wastewater Treatment Plants ◽  
Monitoring And Control ◽  
Standard Signal ◽  
Regression Parameters ◽  
Processing Module ◽  
On Line ◽  
Sensor Information ◽  
And Control

Important indicators for monitoring and control of wastewater treatment plants (WWTP) often have to be obtained from the processing of on-line signal trajectories. Therefore, the quality of sensor instantaneous measurements can be improved significantly if they are complemented with valuable information about the geometric features of their trajectories. The present paper describes the design and implementation of a Standard Signal Processing Architecture (SSPA) from which enriched sensor information is generated automatically. The SSPA has been made up of three complementary modules: the pre-processing module, the storage module and the post-processing module. Moreover, the SSPA has been parameterised so as to allow its adaptation to the specifications of every signal. By performing basic calculations on pre-processed signal trajectories, the storage module produces enriched vectors which collect information of the first and second time derivatives, average and variance values, peak values, linear regression parameters, curvature, etc. Then, the enriched information vectors can be exploited to implement customised monitoring and control tools. In this respect, the effectiveness of the SSPA has been demonstrated in three different practical cases: (1) OUR and KLa identification algorithms; (2) processing of measurements for real-time controllers; and, (3) detection of bend-points in on-line signals of SBR processes.

Automatic buffer capacity based sensor for effluent quality monitoring

1996 ◽  
Vol 33 (1) ◽  
pp. 81-87
Author(s):  
L. Van Vooren ◽  
P. Willems ◽  
J. P. Ottoy ◽  
G. C. Vansteenkiste ◽  
W. Verstraete
Keyword(s):  
Wastewater Treatment ◽  
Buffer Capacity ◽  
Wastewater Treatment Plants ◽  
Data Interpretation ◽  
Full Scale ◽  
Quality Monitoring ◽  
Effluent Quality ◽  
Capacity Curves ◽  
On Line

The use of an automatic on-line titration unit for monitoring the effluent quality of wastewater plants is presented. Buffer capacity curves of different effluent types were studied and validation results are presented for both domestic and industrial full-scale wastewater treatment plants. Ammonium and ortho-phosphate monitoring of the effluent were established by using a simple titration device, connected to a data-interpretation unit. The use of this sensor as the activator of an effluent quality proportional sampler is discussed.

Components of a model-based operation system for wastewater treatment plants

1999 ◽  
Vol 39 (4) ◽  
pp. 103-111 ◽  
Author(s):  
Frank Obenaus ◽  
Karl-Heinz Rosenwinkel ◽  
Jens Alex ◽  
Ralf Tschepetzki ◽  
Ulrich Jumar
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Operation System ◽  
Model Based ◽  
Measuring Devices ◽  
Crucial Component ◽  
Simulation Calculation ◽  
On Line ◽  
Main Components

This report presents the main components of a system for the model-based control of aerobic biological wastewater treatment plants. The crucial component is a model which is linked to the actual processes via several interfaces and which contains a unit which can immediately follow up the current process state. The simulation calculation of the model is based on data which are yielded by on-line measuring devices. If the sensors should fail at times, there are available a number of alternative concepts, some of which are based on the calculations of artificial neural networks or linear methods.

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